I don't necessarily think that. They look fine to me, but I just don't know any better. Like when you've had your first hatch and can't see any problems, but by your hundredth hatch you get a second sense for weak chicks.
They bounce around and their bellies look full. They don't cry, they sleep a lot. I'm seen them nibble hay and feed with their mom. Poop is still yellow and squishy. The buckling already stinks like a buck. The doeling likes to stand on my feet. The Big Boys don't seem to mind them. That's all I know.